McHENRY – Like any family with a newborn during the holidays, Jimmy and Jenna Miller dressed their son, Korbin, in festive outfits. They have a picture of him in a shirt that says “Santa” and one of the happy family in front of a Christmas tree.

After the new year, however, Korbin became ill. Jimmy Miller, in an email to the Northwest Herald, said, “Korbin was a very healthy baby boy until his unexpected illness.”

Korbin, almost 6 weeks old, died Sunday after a five-day stay at Ann & Robert H. Lurie Children’s Hospital in Chicago. The cause of death is still unknown, Jimmy Miller said.